Three radical new energy technologies
November 21, 2012
Three innovative new energy technologies are explored in the current issue of Technology and Innovation — Proceedings of the National Academy of Inventors:
- Tidal currents and ocean waves that can be recovered using ocean thermal conversion technology.
- Infrared thermal radiation (more than half of the power provided by the Sun).
- A new nanophosphor-based electroluminesence lighting device that caters to the exact wavelengths of light required for photosynthesis in indoor, hydroponic agriculture.
Capturing ocean energy
The kinetic energy in the Florida Current and in Florida’s ocean waves can be captured and used, said Howard P. Hanson of the Southeast National Marine Renewable Energy Center at Florida Atlantic University.
“Capturing the kinetic energy of the Florida Current will require both materials advances and new designs for marine current turbines and their efficient deployment,” he said. “The hydrokinetic energy of tidal and open-currents, as well as ocean waves, and the thermal potential of the oceanic stratification, can be recovered using ocean thermal conversion technology.”
Hanson calls this concept “marine renewable energy,” or MRE, and noted in his article that the U.S. Department of Energy has formed three national MRE centers to investigate the resource potential in the oceans and to advance the technology for recovering MRE.
Nanoscale “rectennas” can convert waste thermal energy to electricity
“Converting waste heat to electrical energy can be a reality by using a rectenna, a combination of high frequency antenna and a tunnel diode,” wrote three clean energy engineers from the University of South Florida’s Clean Energy Resource Center.
According to article co-author Yogi Goswami, thermal radiation, or the infrared (IR) portion of the electromagnetic spectrum, is often an overlooked source of renewable energy and more than half of the power provided by the sun — both directed and re-radiated — lies in the infrared part of the spectrum.
“If the IR radiation potential of the earth could be harvested with 75 percent efficiency, it would generate more energy per unit area than a fixed orientation solar cell located in a prime solar location,” said study co-author Subramanian Krishnan.
Rectenna components (antenna and rectifier) used to recapture wasted IR radiation is developed from the decades old concept of using the wave nature of light rather than its thermal effect. Recent advances in nanotechnology have made possible the harvesting of solar energy by rectenna more viable, they said. Recent research has shown that rectenna can be developed at IR frequencies with existing technology and used for IR energy conversion.
Nanotechnology solutions for greenhouse light
Sarath Witanachchi, Marek Merlak and Prasanna Mahawela, of the USF Department of Physics, present the specifics for a new nanophosphor-based electroluminesence lighting device that caters to the exact wavelengths of light required for photosynthesis in indoor, hydroponic agriculture. The new, nanotechnology-based grow light also has the potential to reduce energy costs significantly.
“Conventional technologies used in today’s agriculture are inefficient and lead to natural resource waste and degrade the environment,” said Witanachchi. “Urban agriculture will become the choice in the future. Nanophosphors required to fabricate the active layer of the electroluminescence device are grown by a microwave plasma process, which was developed at the University of South Florida. This process enables the growth of crystalline nanophosphors directly on a substrate as a uniform coating without further processing steps.”
- Howard P. Hanson, Hydrokinetic Energy in the Sunshine State: Challenges of Florida’s Unique Renewable Resource, Technology and Innovation, 2012, DOI: 10.3727/194982412X13462021397615
- S. Krishnan, Y. Goswami, and E. Stefanakos, Nanoscale Rectenna for Thermal Energy Conversion to Electricity, Technology and Innovation, 2012, DOI: 10.3727/194982412X13462021397651
- Sarath Witanachchi, Marek Merlak, and Prasanna Mahawela, Nanotechnology Solutions to Greenhouse and Urban Agriculture, Technology and Innovation, 2012, DOI: 10.3727/194982412X13462021398056